Illumination devices

Abstract

Lighting devices are provided for efficiently distributing light over an area to provided uniform illumination over a wide angle or other tailored illumination patterns. Each light device has at least one light source, at least one collimator for partially collimating light from the light source, and at least one diffuser for diffusing light from the collimator. The diffuser provides diffused light over an area from the diffuser having an intensity that is angularly dependent in accordance with the angular distribution intensity of light outputted from the collimator, so as to provide a predetermined illumination pattern from the device. The light sources and collimators may be provided in one or two-dimensional arrays, and a single diffuser may be formed on each collimator or the diffuser may be along a plate spaced from the collimators.

1. A lighting device comprising:
 at least one source for providing light; 
 at least one first optical element comprising a first end having a spherical first surface and a hyperbolic or elliptic second surface disposed centrally with respect to said spherical first surface, a parabolic outer third surface, and a second end, wherein said first, second, and third surfaces operate upon the light from said source received at said first end to provide light from said second end which is partially collimated; and 
 at least one second optical element for diffusing light from said first optical element. 
 
     
     
       2. The lighting device according to  claim 1  wherein said second optical element diffuses the light from said second end of said first optical element to provide substantially uniform light over an angular range. 
     
     
       3. The lighting device according to  claim 1  wherein said second optical element has a microlens array structure to diffuse the light from said second end of said first optical element to provide light over an area. 
     
     
       4. The lighting device according to  claim 3  wherein said microlens structure represents a randomized microlens array structure. 
     
     
       5. The lighting device according to  claim 3  wherein said second optical element is a plate or sheet having a first surface having said microlens structure and a second surface. 
     
     
       6. The lighting device according to  claim 5  wherein said first surface of the second optical element faces and receives light from said first optical element. 
     
     
       7. The lighting device according to  claim 5  wherein said first surface of the second optical element faces away from said first optical element, and said second faces and receives light from said first optical element. 
     
     
       8. The lighting device according to  claim 1  wherein said second optical element is integrated along a surface of said first optical element to enable said second optical element to diffuse the partially collimated light. 
     
     
       9. The lighting device according to  claim 1  wherein said second optical element spaced from said first optical element. 
     
     
       10. The lighting device according to  claim 1  wherein said light source is one of an LED, remotely illuminated optical fiber, halogen source, OLED, or laser. 
     
     
       11. The lighting device according to  claim 1  further comprising:
 a plurality of ones of said light source; 
 a plurality of ones of said first optical element arranged in an array to receive light from said plurality of ones of said light source; and 
 said second optical element diffuses the light from said plurality of ones of said first optical element. 
 
     
     
       12. The lighting device according to  claim 11  further comprising a plurality of one of said second optical element each disposed for diffusing light from each one of said plurality of ones of said first optical element. 
     
     
       13. The lighting device according to  claim 11  wherein said second optical element is sized to diffuse light received from said plurality of ones of said first optical element. 
     
     
       14. The lighting device according to  claim 11  wherein said array is a two-dimensional array. 
     
     
       15. The lighting device according to  claim 11  wherein said array is a one-dimensional array. 
     
     
       16. The lighting device according to  claim 11  wherein said plurality of ones of said first optical element are formed in said array as a monolithic structure. 
     
     
       17. The lighting device according to  claim 16  wherein said plurality of ones of said first optical element each have different ones of said second end for exiting said partially collimated light, and each of said plurality of ones of said first optical element has a flange connected to other of said plurality of ones of said first optical element to provide said monolithic structure. 
     
     
       18. The lighting device according to  claim 16  wherein the parabolic outer third surface of said plurality of ones of said first optical element merge with each other to form said monolithic structure. 
     
     
       19. The lighting device according to  claim 1  further comprising a housing having said light source, said first optical element, and said second optical element. 
     
     
       20. The lighting device according to  claim 19  wherein said housing has a low profile. 
     
     
       21. The lighting device according to  claim 1  wherein said partially collimated light from said first optical element provides substantially parallel light rays. 
     
     
       22. The lighting device according to  claim 1  wherein said third surface internally reflects light received from said first surface as collimated light toward said second end, and light received by said second surface is collimated toward said second end. 
     
     
       23. The lighting device according to  claim 22  wherein the light collimated by both said second surface and said third surface are substantially parallel to each other when exiting said second end of said first optical element to provide said at least partially collimated light. 
     
     
       24. The lighting device according to  claim 1  wherein said first surface and said second surface are provided by a cavity at said first end into which light from said light source is received. 
     
     
       25. A lighting device comprising:
 at least one source for providing light; 
 at least one first optical element for partially collimating light from said light source to provide an angular distribution intensity narrower than the light from said source, and said first optical element has a first end for receiving the light from said source and a second end outputting said partially collimated light; and 
 at least one second optical element for diffusing light from said first optical element in which said second optical element has an optical diffusion property providing an angularly dependent output light intensity over an area in accordance with the angular distribution intensity of the partially collimated light from said first optical element to provide a redetermined illumination pattern, in which said angular distribution intensity has collimated light exiting said second end in an angular range to said second optical element, and said light from said second end is partially collimated to the extent that light from said first optical element is non-collimated outside said angular range to said second optical element, wherein first optical element comprises: 
 a parabolic rotationally symmetric body having said first end and said second end, in which said first end has a cavity having spherical sides, and a hyperbolic or elliptic center portion; and 
 said body has a parabolic outer surface between said first and second ends for total internally reflecting light received via said spherical sides of said cavity as collimated light toward said second end, in which light received by said center portion is collimated toward said second end, in which the collimated light reflected by said outer surface toward said second end, and light collimated from said central portion toward said second end are substantially parallel to each other when exiting said second end. 
 
     
     
       26. The lighting device according to  claim 25  wherein said center portion is hyperbolic shaped to provide a lens facing said light source. 
     
     
       27. The lighting device according to  claim 25  wherein said center portion is elliptic shaped to provide a lens facing away from said light source. 
     
     
       28. The lighting device according to  claim 25  wherein said light source is centered at the entrance of said cavity. 
     
     
       29. The lighting device according to  claim 25  wherein said cavity is filled with a medium for mounting said light source to said first optical element. 
     
     
       30. The lighting device according to  claim 25  wherein said body extends at said first end to provide a flat base. 
     
     
       31. The lighting device according to  claim 25  wherein said body extends at said first end to provide a collar ring or one or more posts. 
     
     
       32. The lighting device according to  claim 25  wherein said cavity is filled with a material having a lower refractive index than the material of said first optical element. 
     
     
       33. The lighting device according to  claim 25  wherein said cavity is filled with a material having a higher refractive index than the material of said first optical element, and said central portion is elliptical. 
     
     
       34. A lighting device comprising:
 at least one source for providing light; 
 at least one first optical element for partially collimating light from said light source to provide an angular distribution intensity narrower than the light from said source, and said first optical element has a first end for receiving the light from said source and a second end outputting said partially collimated light; and 
 at least one second optical element for diffusing light from said first optical element in which said second optical element has an optical diffusion property providing an angularly dependent output light intensity over an area in accordance with the angular distribution intensity of the partially collimated light from said first optical element to provide a predetermined illumination pattern, in which said angular distribution intensity has collimated light exiting said second end in an angular range to said second optical element, and said light from said second end is partially collimated to the extent that light from said first optical element is non-collimated outside said angular range to said second optical element, wherein said first optical element comprises: 
 a parabolic linearly symmetric body having said first end and said second end, in which said first end has a cavity having spherical sides, and a hyperbolic or elliptic center portion; and 
 said body has a parabolic outer surface between said first and second ends for total internally reflecting light received via said spherical sides of said cavity as collimated light toward said second end, in which light received by said center portion is collimated toward said second end, in which the collimated light reflected by said outer surface toward said second end, and light collimated from said central portion toward said second end are substantially parallel to each other when exiting said second end. 
 
     
     
       35. A collimating optical element comprising:
 a body having a flat light exiting end, and a light entering end with a cavity having spherical sides, and a hyperbolic or elliptic center portion; and 
 said body has a parabolic outer surface between said light exiting and light entering ends for total internally reflecting light received via said spherical sides of said cavity as collimated light toward said light exiting end, and light received by said center portion is collimated toward said light exiting end, in which the collimated light reflected by said outer surface toward said light exiting end, and light collimated from said central portion toward said light exiting end are substantially parallel to each other when exiting said light exiting end. 
 
     
     
       36. The collimating optical element according to  claim 35  wherein said body is rotationally symmetric. 
     
     
       37. The collimating optical element according to  claim 35  wherein said body is linearly symmetric. 
     
     
       38. A luminaire comprising:
 a plurality of light sources; 
 an array of first optical elements each outputting light having an angular distribution intensity in response to light received from each one of said light sources, said angular distribution intensity being characterized by collimated light over an angular range and non-collimated light outside said angular range; 
 a second optical element for diffusing light from said array of first optical elements, in which said second optical element provides an angularly dependent output light intensity in accordance with the angular distribution intensity of said first optical elements to enable said second optical element to output a predetermined light pattern; and 
 a housing having at least said array of first optical elements, and said second optical element, wherein each of said first optical elements comprise: 
 a body having a flat light exiting end, and a light entering end with a cavity having spherical sides, and a hyperbolic or elliptic center portion; and 
 said body has a parabolic outer surface between said light exiting and light entering ends for total internally reflecting light received via said spherical sides of said cavity as collimated light toward said light exiting end, and light received by said center portion is collimated toward said light exiting end. 
 
     
     
       39. The luminare according to  claim 38  wherein said housing is of a low profile. 
     
     
       40. The luminare according to  claim 38  wherein said array represents one of a one or two-dimensional array. 
     
     
       41. The luminare according to  claim 38  wherein said light sources are each one of an LED, remotely illuminated optical fiber, halogen source, OLED, or laser. 
     
     
       42. The luminare according to  claim 38  wherein said second optical element is a plate or sheet having a surface with a microlens structure to provide said angularly dependent output light intensity in accordance with the angular distribution intensity of said first optical elements. 
     
     
       43. The luminaire according to  claim 38  further comprising a plurality of ones of said second optical elements each capable of diffusing light to provide a different predetermined light pattern, and said plurality of ones of said second optical elements being interchangeable with each other in said housing. 
     
     
       44. The luminaire according to  claim 38  wherein one or more of said first optical elements of said array are formed as a monolithic structure. 
     
     
       45. The lighting device according to  claim 38  wherein the collimated light reflected by said outer surface toward said light exiting end, and light collimated from said central portion toward said light exiting end are substantially parallel to each other when exiting said light exiting end. 
     
     
       46. The luminaire according to  claim 38  further comprising a board having said light sources each disposed to provide light to different ones of said first optical elements, and said housing further comprises said board. 
     
     
       47. The luminaire according to  claim 38  wherein said angularly dependent output light intensity of said second optical element is complementary to said angular distribution intensity of first optical elements to provide a light pattern from said second optical element which is substantially uniform. 
     
     
       48. An optical element comprising a body having a first end with a spherical first surface and a hyperbolic or elliptic second surface disposed centrally with respect to said spherical first surface, a second end, and a parabolic outer third surface between said first and second ends, wherein said third surface internally reflects any light received from said first surface toward said second end and said second surface transmits any light received toward said second end to provide light exiting said body at said second end which is at least partially collimated when light is received at said first end by said first and second surfaces.